Mule Deer
The mule deer (Odocoileus hemionus) is a deer indigenous to western North America; it is named for its ears, which are large like those of the mule. There are believed to be several subspecies, including the black-tailed deer. Unlike the related white-tailed deer (Odocoileus virginianus), mule deer are generally more associated with the land west of the Missouri River, and more specifically with the Rocky Mountain region of North America. Mule deer have also been introduced to Argentina. Description The most noticeable differences between white-tailed and mule deer are the size of their ears, the color of their tails, and the configuration of their antlers. In many cases, body size is also a key difference. The mule deer's tail is black-tipped, whereas the whitetail's is not. Mule deer antlers are bifurcated; they "fork" as they grow, rather than branching from a single main beam, as is the case with whitetails. Each spring, a buck's antlers start to regrow almost immediately after the old antlers are shed. Shedding typically takes place in mid-February, with variations occurring by locale. Although capable of running, mule deer are often seen stotting (also called pronking), with all four feet coming down together. Black-tailed deer have also been introduced to Kauai, (Hawaii). Seasonal behaviors In addition to movements related to available shelter and food, the breeding cycle is important in understanding deer behavior. The "rut" or mating season usually begins in the fall as does go into estrus for a period of a few days and males become more aggressive, competing for mates. Does may mate with more than one buck and go back into estrus within a month if they do not settle. The gestation period is about 190–200 days, with fawns born in the spring, staying with their mothers during the summer and being weaned in the fall after about 60–75 days. Mule deer females usually give birth to two fawns, although if it is their first time having a fawn, they often only have one. A buck's antlers fall off during the winter, to grow again in preparation for the next season's rut. The annual cycle of antler growth is regulated by changes in the length of the day. The several predators other than humans of mule deer include coyotes, gray wolves and mountain lions. These three leading natural predators often select weak, sickly, or young deer to kill, but will also take down the largest and healthiest mule deer with some regularity, as well. Bobcats, wolverines, American black bears, and brown bears are capable of preying on adult deer, but usually either only attack fawns or infirm specimens or eat the deer after it has died naturally. Foraging Mule deer consume a wide variety of plants, and their preferences vary widely geographically as well as seasonally, but they are primarily browsers on woody vegetation and eat relatively little grass. They readily adapt to agricultural products and landscape plantings. Summer In summer, mule deer chiefly forage on not only herbaceous plants, but also various berries (including blackberry, blueberry, salal, and thimbleberry). They also use grasses more than in winter. Mule deer are known to forage in summer on California buckeye leaves, though it may be toxic. Winter In winter, these deer forage on conifers (especially Douglas-fir, cedar, Taxus yews, juniper), and twigs of deciduous trees and shrubs (esp. aspen, willow, dogwood, serviceberry, and sage). In season, they eat acorns and apples. Over much of the species range, snow and ice cover many food sources and the food that is accessible grows slower. The deer's metabolism slows and individuals become less active to survive in an environment with less food. A large fraction of the deaths in a mule deer population occur in the winter, especially during the first year of life Category:Deer Category:Animals Category:Mammals Category:Herbivores